Electric lamp



g- 11, 1931- H. A. DOUGLAS 1,817,975

ELECTRIC LAMP Filed Oct. 23, 1929 2 Sheets-Sheet l fig Aug. 11, 1931. H,A. DOUGLAS ELECTRIC LAMP Filed Oct. 23, 1929 2 Sheets-Sheet 2 PatentedAug. 11, 1931 UNITED STATES PATENT OFFICE ELECTRIC LAMP Applicationfiled October 23, 1929. Serial No. 401,723.

My invention relates to lamp structures employing sockets for receivingthe bases of incandescent lamps. The invention has for its object theprovision of improved means for fixing the lamps in predeterminedositions with respect to the sockets receiving the bases of the lamps.The invention finds an important use in connection with )lamps havingconcave reflectors that are m equipped with holders for the sockets andhaving in association therewith means for predetermining the positionsof the sockets with respect to the holders and reflectors. A lamp thusconstructed will direct light in a fixed path with respect to the axisof the reflector, thereby avoiding difliculty now frequently encounteredin the adaptation of reflecting lamps to automotive vehicles, bodily orother adjustment of the lamps having frequently been required when theusers happen to find that the light is improperly directed.

In my copending application Serial No. 403,613 filed October 30, 1929(Case 256),

I have broadly claimed a lamp receiving. socket within a holder andsmaller in cross section than the holder, and means pressing the socketlaterally against one side of the holder. The structure disclosed in theg aforesaid copending application employs a concave reflector withrespect to which the socket holder is fixed, the bore of the socketholder being in register with an opening that is formed through thereflector to permit of the insertion of the base of an incandescentlamp. The structure of the aforesaid application is also inclusive ofspaced apart spacing means intervening between the holder and socket inthe place at which the socket is pressed against the holder.

The structure herein disclosed is preferably inclusive of all of thecharacteristics above generally set forth. A portion of the structureinvolving my present invention is inclusive of an incandescent lamphaving its base received in said socket and which base is smaller incross section than the bore of the socket, and a spreader interposed between adjacent side portions of the lamp base and socket to force thelamp base against a side of the socket. My structure preferably fixesthe location of the filament with respect to the reflector. By fixin theposition of the lamp longitudinally o the socket the necessity of aspecial design for the reflector which has hitherto been roposed toprocure the same lighting e ect of the filament in different positionsalong the reflector axis is avoided. The invention, however, is not tobe thus limited.

If the holder be associated with a reflector, the position of the lampfilament with respect to the reflector is assured, it being understoodthat the lamp filaments of the incandescent lamps which are to be usedin the structure of my invention preferably occupy predetermined uniformpositions with respect to the lamp bases. To further assure the precisepositions of the lamps, I desirably provide V-shaped seats in thebayonet slots that receive the ba onet pins upon the lamps, so that thelamps are brought to a uniform position rotatively.

The invention will be more fully explained in connection with theaccompanying drawings, showing the preferred embodiment thereof, and inwhich Fig. 1 is a plan View with a portion of the reflector shown insection; Fig. 2 is a View from beneath, part of the bulb being brokenaway; Fig. 3 is a; sectional view on line 3-3 of Fig. 1; Fig. 4 is asectional view on line H of Fig. 3. Fig. 5 is a sectional View on line55 of Fig. 3; Fig. 6 is a sectional ,view on line 66 of Fig. 3; Fig. 7is a perspective view illustrating component parts of the structure inseparated relation; and Fig. 8 is a sectional elevation taken throughthe axis of the parabolic reflector.

The lamp illustrated includes a housing or back element 1 having abracket 2 on its bottom side by which it may be assembled with theautomotive vehicle or other support, as indicated. The housing or back 1encloses a parabolic reflector 3 which is formed with a grooved flange 4at its forward end. This flange is pressed against a rim 5, providedupon the housing, by an assembling ring 6. This assembling ring alsopresses the light transmitting closure 7, usually of glass, againstagasket 8 which is seated in the flange 4.

The generally cylindrical socket holder 9 has its forward end passedthrough a circular ening formed through the crown of the re ector, inthe embodiment of the invention shown. The forward end of the holder 9is formed with flanges 10 and 11 between which the surrounding edgeportion of the reflector is clamped, whereby the holder and reflectorare maintained coaxial, in the structure illustrated.

The generally cylindrical lamp socket 12 is held in assembly with andwithin the holder 9 b the means hereinafter set forth. This soc et ispreferably formed with a single bayonet slot or channel 13 for receivinga bayonet projection 14 upon the base 15 of an incandescent lamp. Thisbayonet projection is maintained in a V-shaped retaining seat 13 of thebayonet slot by any suitable means, the V-shaped seat holding the lampfrom rotative movement. The means illustrated is inclusive of a coiledspring 16 which surrounds a plunger 17 constituting a circuit terminaland presses forwardly upon the plunger head 18 and rearwardly upon theflan e 19 of a metallic guiding sleeve 20. This guiding sleeve ismounted upon an insulating disc 21 which is fixedly assembled with andwithin the rear end of the socket 12. The plunger head 18 pressesagainst a contact 22 which is carried by the generally cylindrical lampbase 15 which is made of insulating material.

The lamp structure illustrated is a so-called single pole structure,though the invention is not to be thus limited. Where a single polestructure is employed, the contact 22 is upon the axis of the lamp base.A stiff leading in wire 24 establishes connection between the contact 22and one terminal of the filament 25. Another stiff leading in wire 26establishes a connection between the other terminal of the filament andthe metallic sheath 27 which surrounds the insulating portion of thelamp base and, from the point of view of my invention, also constitutesa p: rt or enlar ement of the lamp base. The body of the re ector, theholder 9, and

'the socket 12 are grounded and when the lamp is in place the sheath 27is also grounded as it has connection with the holder, as will morefully appear.

In carrying out my invention the cross section of the socket 12 issmaller than the bore of the holder 9 and the base of the lamp,inclusive of its sheath 27, is smaller, in cross section, than the boreof the socket.

Spaced apart spacing means intervene between the holder 9 and the socket12. These spacing means are preferably in the form of ribs 28 whichextend longitudinally of the holder and socket. Each rib is desirablyintegrally formed with one of the elements 9 or 12, both ribs beingshown as being integrally formed with the holder. The ribs are spacedless than 180 degrees apart, preferably 120 degrees apart. The means forpressing the socket 12 against the holder 9 is desirably inclusive oftwo spring tongues 29 which are integrally formed with the holder 9. Thesocket 12 is formed with a lug 30 which is snugly engaged between recessed portions of the spring tongues 29 and having an extension 30'engaging the rear wall 9' of a slot 9 that is formed in the holder tofix the socket with respect to the holder. This slot also serves to formthe spring tongues.

The spreader employed for positioning the lamp base within and withrespect to the lamp socket is desirably inclusive of the aforesaid lug30 whose inner face is a wedging face that takes part in the spreadingaction. The spreader is also inclusive of a plunger 31 having one endentered between the lug 30 and the base of the lamp. A spring 32surrounds the shank of the plunger. This spring is bottomed, at one end,upon the disc 21 and is coupled, at its other end, with a forwardportion of the plunger. The spring is under compression and exertsforward movement upon the plunger which passes through and is in slidingengagement with said disc. The plunger has a hook end 31 by which theextent to which it is forwardly pressed is limited when the lamp ismoved from the socket. The plunger serves to press the lamp base againsta side of the socket that i" opposite the lug 30. Spaced apart distancepreserving means are interposed between the lam socket and the lamp basewhere the base is pressed toward the socket. This distance preservingmeans is preferably in the form of two ribs 33 which are less than 180degrees apart, preferably 120 degrees apart. Each rib is preferablyintegrally formed with one of the elements 12 or 27. In the embodimentof the invention shown both ribs are integrally formed with the sheath27. By the structure illustrated, identically constructed lamps havingtheir filaments in exactly the same positions with respect to the lampbases may be interchangeably assembled with the lamp sockets with theassurance that the filments will occupy one predetermined location withrespect to the reflector axes.

While the lamp and socket assembly herein disclosed is preferably usedin connection with a lamp structure that includes a concave reflector,the invention is not to be thus limited.

Changes may be made without departing from the invention.

Having thus described my invention, I claim:

of an incandescent lamp havin 1. The combination w1th a lamp socket; ofan-incadescent lamp having its base received in said socket and whichbase is smaller in cross section than the bore of the socket; and aspring pressed wedging element interposed between adjacent side portionsof the lamp base and socket to force the lamp base against a side of thesocket.

2. The structure of claim 1 wherein there are spaced apart spacing meansbetween the socket and lamp base where the lamp base is pressed towardthe socket.

3. The structure of claim 1 wherein spaced apart spacing ribs extendinglongitudinally of the socket and lamp base in tervene between the socketand lamp base where the lamp base is pressed toward the socket.

4. The combination with a lamp socket; of an incandescent lamp havingits base received in said socket and which base is smaller in crosssection than the bore of the socket; and a spreader interposed betweenadjacent side portions of the lamp base and socket to force the lampbase against 'a side of the socket, said spreader being inclusive of awedging element interposed between side portions of the socket and baseand a spring which presses said wedging element into spreadingengagement with the socket and lamp base.

5. The structure of claim 4 wherein there are spaced apart spacing meansbetween the socket and lamp base where the lamp base is pressed towardthe socket.

6. The structure of claim 4 wherein spaced apart spacing ribs extendinglongitudinally of the socket and lamp base intervene between the socketand lamp base where the lamp base is ressed toward the socket.

7. The com ination with a lamp socket;

its base received in said socket and which ase is smaller in crosssection than the bore of the socket; and a spreader interposed betweenadjacent side portions of the lamp base and socket to force the lampbase a alnst a side of the socket, said spreader being inclusive of awedgingelement interposed between side portions of the socket and baseand a spring which is carried by the socket and presses said wedgingelement into spreading engagelllnent with the socket and lamp base.

8. e structure of claim 7 wherein there are spaced apart spacing meansbetween the socket and lam base where the lamp base is pressed towar thesocket.

9. The structure of claim 7 wherein spaced apart spacing ribs extendinglongitudinally o the socket and lamp base intervene between the socketand lamp base where the lamp base is pressed toward the socket.

10. The combination with a lamp socket; of an incandescent lam havin itsbase received in said socket an which ase is smaller in cross sectionthan the bore of the socket; and a spreader interposed between adjacentside portions of the lamp base and socket to force the lamp base againsta side of the socket, said spreader being inclusive of a wedging elementinterposed between side portions of the socket and base and a springwhich presses said wedgin element into spreading engagement with t esocket and lamp base, the socket having a cam portion which is the partof the socket with which the wedging element has engagement.

11. 'The structure of claim 10 wherein there are spaced apart spacingmeans between the socket and lamp base where the lamp base is pressedtoward the socket.

12. The structure of claim 10 wherein spaced apart spacing ribsextending longitudinally of the socket and lamp base intervene betweenthe socket and lamp base where the lamp base is pressed toward thesocket.

13. The combination with a lamp socket; of an incandescent lamp havingits base received in said socket and which base is smaller in crosssection than the bore of the socket; and a spreader interposed betweenadjacent side portions of the lamp base and socket to force the lampbase against a side of the socket, said spreader being inclusive of awedging element interposed between side portions of the socket and baseand a spring which is carried by the socket and presses said wedgingelement into spreading engagement with the socket and lamp base, thesocket having a cam portion which is the .part of the socket with whichthe wedging element has engagement.

14. The structure of claim 13 wherein there are spaced apart spacingmeans between the socket and lamp base where the lamp base is pressedtoward the socket.

15. The structure of claim 13 wherein spaced apart spacin ribs extendinglongitudinally of the s05; tervene between the socket and lamp basewhere the lamp base is pressed toward the socket.

In witness whereof, I hereunto subscribe my name.

HARRY A. DOUGLAS.

et. and lamp base in-

